[brcidd]

I've never seen a negative cable at a starter-- Starter grounds through its body as mounted back to system and ground wire from engine block to battery negative. You have NO negative cable at the starter- and don't try to attach the cable in question anywhere else- it has to be a hot lead....

A spark when you attached a positive cable to battery is to be expected now days- with modules that come to life etc.

Wire it like your photo.

It is hard to see- but is there a load wire coming off the top post? This may be why you are confused- your car may be wired so that the vehicle load comes from solenoid post instead of battery- if so, yes, attach it to the top post along with the battery hot cable.

The purple wire is your starter hot lead from your ignition switch- it becomes 12 positive when key is turned to "start" and tells starter to energize the coil which switches 12v to the starter through the big wires.